Ankle Pain: Sprains and Instability

The ankle is frequently injured in sports. In our recently published "Ohio Runner's Survey of Running Injuries," 12 percent of the injuries reported were of the ankle. In a 1979 Consumer Product Safety Commission Survey, there were reported over 415,000 people who sustained ankle injuries per year. One third of those injured in basketball were ankle injuries, while 30% were in volleyball, 24% in track and field and 32% in tennis and badminton. Golf accounted for 8% with ankle in juries, and the lowest incidence was found in weightlifting.

Anatomy of the Ankle Joint
The ankle joint is made up of three bones, two from the leg and one from the foot. The end of the leg bones, the tibia and the fibula, have enlargements called malleoli. These form the top half of the joint while the foot bone, the talus, makes up the bottom half. The surface of these bones are mostly covered with cartilage. The cartilage al lows the joint to work in a smooth fashion which is mostly up and down. Stability is achieved by the strong ligaments on both sides of the joint, and by the structural alignment of the bones them selves. Surrounding these bones is a joint capsule, a balloon-like structure, which is lined with specialized cells that manufacture lubrication for the joint. Thirteen tendons cross over the joint from muscles in the leg, allowing motion and providing more stability.

Functional Relationships
The ankle joint, with its bony structure and maze of ligaments, is designed to support our entire body weight and allow the proper amount of motion that leads to good foot and leg function. It is important to keep in mind several points. First, the ankle and how it functions is influenced by the structures above and below it; specifically, the leg and the foot. Any malalignment from either direction affects the ankle. An example of this would be a foot structure that is tilted toward the inside of the leg. This puts too much strain on the ligaments and may predispose towards ankle sprains. Second, the job of the ligaments is to hold bones in place. When ligaments are damaged their ability to stabilize the ankle joint is lessened and sprains result. Third, the muscles that cross the ankle joint not only help move it but stabilize it also. There must be good balance between these muscles and how they pull; otherwise the ankle will not be in its normal position.

Therefore, the ankle joint needs to be mobile and provide stability. Too loose a structure leads to injury; too tight results in restricted motion. There are five general classifications of injuries to the ankle pertaining to anatomical structures. They involve the ligaments, bones, soft tissue, cartilage and the muscle-tendon complex. Examples would be an ankle sprain, ankle fracture, inflammation of the lining of the joint (synovitis), defect or break in the cartilage, and a calf muscle-tendon tear, respectively.

Many times an injury involves more than one of the above, and evaluation and treatment must be directed at each separate component. For clarity let's discuss the most common injuries individually.

Ankle Sprains
Ankle sprains are very common and often disabling. The saying "a sprain is worse than a fracture" is often true. A sprain not treated properly, or left alone, is often worse than a well-treated fracture. A broken bone will heal when aligned and kept in its proper position. Once injured, a stretched out or torn ligament may become a chronic problem if not properly treated. Too often the patient is seen in an emergency room or by a doctor who x-rays the ankle to rule out a fracture, then simply wraps it and sends the patient on his way.

There are two basic types of ankle sprains. The inversion sprain, which accounts for 85 percent of all ankle sprains, occurs when the foot severely turns in with relation to the leg. The other is the eversion sprain. This happens when the foot is turned out in relation to the leg. This type of sprain is infrequent not only because of the mechanism involved, but because the ligaments on the inside of the ankle are much stronger than those on the outside, and, therefore, are rarely injured.

There are three main ligaments on the outside of the ankle. They provide stability as well as control the mobility of the ankle joint. When an inversion sprain occurs these ligaments are stretched or torn. The severity of the sprain is classified in three degrees. The first degree is when there is swelling and pain but no instability of the ankle joint. The second degree has swelling, pain, and some instability usually involving a single tear of a ligament. The third degree has pain, swelling, and marked instability denoting at least a two ligament tear.

If you sprain your ankle and it is only slightly painful, doesn't swell, isn't tender to the touch and you are able to return to feeling good by walking it off in a short period of time, then no treatment is necessary. However, not all sprains are alike. If the ankle swells, gets black and blue, is painful to the touch, or hurts to walk on, seek professional examination and treatment. You can treat the in jury before you get to a doctor by doing three things: one, use ice to reduce swelling and provide some relief of pain; two, apply compression with an Ace bandage to keep the swelling down, and three, elevate the leg to help force the fluids away from the injured area.

When you are seen by a doctor, your examination should include an evaluation of the ankle and foot. Frequently an ankle sprain is associated with

a fracture of the fifth metatarsal, a bone on the outside part of the foot. X-rays are used to rule out broken bones, while special stress x-rays are taken to evaluate the integrity of the ligaments. Some people have increased laxity of the ligaments which is normal, so it is important in a complete and thorough examination to take x-rays of the uninjured side for comparison.

The aims of treatment are to return the injured ankle ligaments to normal. This is done usually with RICE: Rest, Ice, Compression and Elevation during the initial stages; immobilization, if necessary, until the structures heal; and then physical therapy to regain strength and mobility.

Taping is widely used as a measure to prevent ankle sprains. The University of Washington in an article titled "The Measurable Support of the Ankle Joint by Conventional Methods of Taping" reported some interesting facts. It described four methods of taping, and these were evaluated both before and after exercise. The study reported that regardless of the type used, after ten minutes of vigorous physical activity, forty to fifty percent of the supporting strength of the strappings was lost. The real aim of the taping is to prevent the ankle joint from exceeding its physiological limits of motion. Strapping is still the most reliable and effective method of protecting the ankle joint.

There are several methods for dealing with chronic or long term instability of the ankle. Strengthening exercises are sometimes useful and high-top or three-quarter shoes help. Sometimes a shoe with a flared heel on its outer side or the use of an orthotic prevents the ankle from turning over. In those individuals with extreme laxity of the ligaments, surgical repair is used. This is often successful and returns the ankle to normal function, although there may be a long recovery period. Newer arthroscopic techniques (surgery through a very tiny incision) have been developed which decrease this long recovery time.

Muscle-Tendon Injuries
There are two muscle tendon injuries that are commonly involved in ankle problems; Achilles Tendonitis and peroneal Tendonitis.

The Achilles tendon is often irritated or injured and must be carefully managed to insure a full recovery. The best treatment is to stop running or exercising completely until the inflammation quiets down. Physical therapy, anti-inflammatory drugs, taping, or heel lifts are often helpful. Steroid injections should be avoided since they may weaken the tendons. Prevention is usually the best treatment, and a biomechanical examination with use of orthotics helps to avoid or to control this aggravating condition.

The peroneal muscles and their tendons are used to evert (or turn outward) the foot on the leg. At the level of the ankle joint, they are in a groove just in back of the outside ankle bone and stabilized in this groove by a thick, fibrous band. Sometimes this groove isn't deep enough or the band is stretched out or torn. This allows these tendons to snap out of position or dislocate. Treatment consists of casting. If this is not satisfactory, surgery is necessary.

Soft Tissue Inflammation of the Ankle Joint
There is a balloon-like structure, the capsule that surrounds the bones of the ankle joint. It is flexible and lined with a tissue (synovium) that helps lubricate the joint for proper motion. Almost any kind of injury can and usually does involve these structures. Sometimes though, there isn't a specific in jury that the patient can recall; he just simply has a painful, swollen ankle for no apparent reason. It may bother him more with activity or may be painful constantly. A thorough examination might reveal no apparent structural problem. Usually supportive therapy in the form of rest, immobilization and physical therapy is adequate to resolve the problem. Anti-inflammatory drugs or injections may also be necessary.

In chronic cases not responsive to conventional treatment, arthroscopy has proven to be a valuable tool. Frequently this procedure is done on an outpatient basis or in the office using local anesthesia. Here the inside of the ankle is visualized through a small telescope (arthroscope). It is placed inside the joint through a tiny incision that requires only one stitch to close. Attached to the arthroscope is a miniature television camera which is hooked up to a video recorder and television monitor. The joint, its lining, capsule and ligaments are examined and, if needed, small instruments can be introduced through a second small incision to trim away the abnormal tissue that may be interfering with the free function of the joint and thereby causing the pain. A bandage is left on for three days, after which Band-Aids and a support stocking are used for several weeks. Relief is almost instantaneous. Thus far the results have been very gratifying.

Cartilage Defects
In some instances cartilage inside the ankle joint wears away or breaks. The joint therefore cannot function properly, loses much of its gliding mechanism; and this results in pain. Injuries frequently cause these conditions, but wear and tear alone may be the cause. The ankle joint, like the knee joint, bears all of the body's weight. Activities we normally participate in - such as running, baseball, basketball, soccer and even ballet - can cause a wearing away or fatigue fracture of the joint cartilage.

Cartilage defects are insidious. The examination of the ankle usually shows no decreased range of motion or instability. X-rays are the key to diagnosis. Sometimes even standard x-rays are not fully adequate and specialized studies need to be done. The only treatment I have found to be satisfactory is removal of the affected cartilage. Small drill holes are then made into the bone and the body then grows a new covering in the previously damaged area. Newer techniques using the arthroscope as discussed previously can be used to dramatically reduce recovery time when compared to the traditional open surgical methods.

Ankle Fractures
Occurring much less frequently are ankle fractures. These usually happen as a result of extreme force on the bones. Fractures of one or both bones of the ankle or fracture with dislocation of the bones occur. The immediate treatment is again RICE. X-rays are mandatory and the bone or bones broken must be put back together (reduced) and then maintained in that position until healed. This may be done by closed reduction with casting, or by open reduction, which involves surgery and the use of screws, wires or metallic plates to keep the bones in place. The realignment and repair of ankle fractures is critical to restore normal function. In a Swiss study of ankle fractures, they found that only one millimeter malalignment or shortening of the ankle joint resulted in degenerative joint disease (arthritis) developing in over ninety percent of the ankles five years after the injury. Proper treatment is a must.

Summary
The ankle joint complex is a marvelous joint that enables us to function properly and participate in a myriad of activities in our daily lives. Many books, articles and papers are devoted entirely to its anatomy, biomechanics, mechanism of injury and repair and rehabilitation. Our continuing study and review of this all-important area will add to our understanding in prevention and treatment.